In the latest round between President Donald Trump and his former White House aide, Omarosa Manigault Newman, Trump’s campaign has filed an arbitration action, alleging that Manigault Newman has broken a 2016 confidentiality agreement by publishing a tell-all book.

The action comes as Trump has publicly disparaged Manigault Newman, the former reality television star. Writing on Twitter on Tuesday, the president called her “that dog” and a “crying lowlife,” and he praised his chief of staff, John Kelly, for firing her last year, reports the Post.

Manigault Newman has also publicized a series of private recordings including one of her firing in the White House Situation Room. And she says she personally heard a tape on which Trump says the N-word.